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United States Patent |
5,012,840
|
Betzler
|
May 7, 1991
|
Fluid flow indicator system
Abstract
A fractional flow indicator system by which flow in a fluid dispensing
conduit is visually indicated using an improved fractional flow diverting
element which utilizes a venturi effect rather than a check valve to
create a fractional flow pressure differential to induce a fractional
fluid flow through a flow indicator. The flow diverting element of the
present invention has no moving parts, is easy and relatively inexpensive
to manufacture, and does not restrict or reduce the pressure of the main
fluid stream flowing therethrough. In accordance with the preferred
embodiment, the flow diverting element is constructed from standard elbow
components and a short length of copper tubing. The flow indicator system
further includes an improved flow indicator having a compact construction
with few working parts, which is easy to manufacture, less expensive to
produce, and which provides a longer service life than conventional
indicators. In particular, the flow indicator of the present invention
does not include a multi-part pedestal, a precisely machined diverting
nozzle, and a corresponding precisely machined port.
Inventors:
|
Betzler; Mark H. (McDaniel, MD)
|
Assignee:
|
Dresser Industries, Inc. (Dallas, TX)
|
Appl. No.:
|
521058 |
Filed:
|
May 2, 1990 |
Current U.S. Class: |
137/559; 116/273; 137/599.01; 222/40 |
Intern'l Class: |
F16K 037/00 |
Field of Search: |
137/559,599,561 A,561 R
116/273,274,DIG. 7
222/40
|
References Cited
U.S. Patent Documents
445909 | Feb., 1891 | Shontz | 137/599.
|
846100 | Mar., 1907 | Estep | 137/599.
|
1345733 | Jul., 1920 | Ayres | 116/273.
|
1730118 | Oct., 1929 | Cobb | 116/273.
|
1730127 | Oct., 1929 | Davenport | 116/273.
|
2008460 | Jul., 1935 | McCandless | 222/40.
|
2678624 | May., 1954 | Grise et al. | 116/273.
|
2836142 | May., 1958 | Ainsworth | 116/274.
|
2847969 | Aug., 1958 | Woodruff | 116/273.
|
3776274 | Dec., 1973 | Riley | 137/599.
|
4819577 | Apr., 1989 | Campau | 116/273.
|
Primary Examiner: Rivell; John
Claims
What is claimed is:
1. A flow indicator system for use with a fuel dispenser, said system
comprising a flow indicator including a substantially rectangular base
having fractional flow input and output passages, a transparent
dome-shaped cover having a circular open end and a circumferential flange
adjacent said open end, one or more movable flow indicating bodies located
within a chamber created by said base and said cover, a retainer bracket
for attaching said cover to said base, resilient means providing a fluid
tight seal between said transparent cover and said base, an annular recess
in the front surface of said base adapted for receiving the open end of
said cover and intersecting with a small angled fluid inlet extending from
said input passage and a larger sized fluid outlet extending from said
output passage, and wherein the width of said annular recess is less than
the diameter of said flow indicating bodies and the depth of said annular
recess is sufficient to prevent said flow indicating bodies from blocking
said fluid outlet, and a fractional flow diverting element including an
elbow for angularly directing the flow of fluid, said elbow including a
major inlet for receiving fluid from a fluid supply conduit, a surface
opposite said major inlet for angularly directing the flow of fluid
through said elbow, a major outlet for discharging the angularly directed
fluid flow, a fractional output port for diverting a fraction of said
fluid received by said major inlet at a first fluid pressure, and a
fractional input port for returning fluid diverted by said fractional
output into said angularly directed fluid flow in the area of said major
outlet and at a second fluid pressure less than said first fluid pressure.
2. The flow indicator system of claim 1, wherein said fractional output
port comprises a first threaded opening adapted to receive a first
small-sized fitting.
3. The flow indicator system of claim 1, wherein said fractional input port
comprises a second threaded opening adapted to receive a second
small-sized fitting which supports a section of tubing extending
substantially from said second threaded opening to said major outlet.
4. The flow indicator system of claim 2, wherein said fractional input port
comprises a second threaded opening adapted to receive a second
small-sized fitting which supports a section of tubing extending
substantially from said second threaded opening to said major outlet.
5. The flow indicator system of claim 4, wherein each of said first and
second small-sized fittings are elbow fittings.
6. A flow indicator system for use with a fuel dispenser, said system
comprising a fractional flow diverting element including an elbow for
angularly directing the flow of fluid, said elbow including a major inlet
for receiving fluid from a fluid supply conduit, a surface opposite said
major inlet for angularly directing the flow of fluid through said elbow,
a major outlet for discharging the angularly directed fluid flow, a
fractional output port for diverting a fraction of said fluid received by
said major inlet at a first fluid pressure, and a fractional input port
for returning fluid diverted by said fractional output into said angularly
directed fluid flow in the area of said major outlet and at a second fluid
pressure less than said first fluid pressure, wherein said system further
comprises a flow indicator including a substantially rectangular base
having fractional flow input and output passages, a transparent
dome-shaped cover having a circular open end and a circumferential flange
adjacent said open end, one or more moveable flow indicating bodies
located within a chamber created by said base and said cover, a retainer
bracket for attaching said cover to said base, resilient means providing a
fluid tight seal between said transparent cover and said base, an annular
recess in the front surface of said base adapted for receiving the open
end of said cover and intersecting with a small angled fluid inlet
extending from said input passage and a larger sized fluid outlet
extending from said output passage, and wherein the width of said annular
recess is less that the diameter of said flow indicating bodies and the
depth of said annular recess is sufficient to prevent said flow indicating
bodies from blocking said fluid outlet, and wherein each of said input and
output passages comprises a threaded bore in the back surface of said
base.
7. A flow indicator system of claim 6, wherein each of said threaded bores
is adapted to receive a small-sized elbow fitting.
8. The flow indicator system of claim 7, wherein said fractional output
port of said diverting element comprises a first threaded opening adapted
to receive a first small-sized elbow fitting.
9. A flow indicator system of claim 8, wherein said fractional input port
of said diverting element comprises a second threaded opening adapted to
receive a second small-sized elbow fitting which supports a section of
tubing extending substantially from said second threaded opening to said
major outlet.
10. A fractional flow diverting element comprising a valveless right angle
inverted flare elbow for angularly directing the flow of fluid, said elbow
including a major inlet for receiving fluid from a fluid supply conduit, a
surface opposite said major inlet for angularly directing the flow of
fluid through said elbow, a major outlet for discharging the angularly
directed fluid flow, a fractional output port for diverting a fraction of
said fluid received by said major inlet at a first fluid pressure, and a
fractional input port for returning fluid diverted by said fractional
output into said angularly directed fluid flow in the area of said major
outlet and at a second fluid pressure less than said first fluid pressure.
11. The fractional flow diverting element of claim 10, wherein said
fractional output port comprises a first threaded opening adapted to
receive a first small-sized fitting.
12. The fractional flow diverting element of claim 10, wherein said
fractional input port comprises a second threaded opening adapted to
receive a second small-sized fitting which supports a section of tubing
extending substantially from said second threaded opening to said major
outlet.
13. The fractional flow diverting element of claim 12, wherein said
fractional output port comprises a first threaded opening adapted to
receive a first small-sized fitting.
14. The fractional flow diverting element of claim 13, wherein each of said
first and second small-sized fittings are elbow fittings.
15. A flow indicator comprising a substantially rectangular base having
fractional flow input and output passages, a transparent dome-shaped cover
having a circular open end and a circumferential flange adjacent said open
end, one or more movable flow indicating bodies located within a chamber
created by said base and said cover, a retainer bracket for attaching said
cover to said base, resilient means providing a fluid tight seal between
said transparent cover and said base, an annular recess in the front
surface of said base adapted for receiving the open end of said cover and
intersecting with a small angled fluid inlet extending from said input
passage and a larger sized fluid outlet extending from said output
passage, and wherein the width of said annular recess is less than the
diameter of said flow indicating bodies and the depth of said annular
recess is sufficient to prevent said flow indicating bodies from blocking
said fluid outlet.
16. The flow indicator of claim 15, wherein each of said input and output
passages comprises a threaded bore in the back surface of said base.
17. The flow indicator of claim 16, wherein each of said threaded bores is
adapted to receive a small-sized elbow fitting.
18. The flow indicator of claim 15, wherein said retainer bracket extends
beyond at least one lateral edge of said base for mounting said indicator
to a dispenser.
19. The flow indicator of claim 15, wherein said resilient means comprises
a pair of o-rings, one of said o-rings being located between said
circumferential flange and said annular recess and the other of said
o-rings being located between said circumferential flange and said
retaining bracket.
20. The flow indicator of claim 15, wherein the diameter of said small
angled fluid inlet is about 1/2 the diameter of said larger sized fluid
outlet.
21. In a fuel dispenser having a fractional flow indicator system, the
improvement comprising:
a fractional flow diverting element including a valveless right angle
inverted flare elbow for angularly directing the flow of fluid, said elbow
including a major inlet for receiving fluid from a fluid supply conduit, a
surface opposite said major inlet for angularly directing the flow of
fluid through said elbow, a major outlet for discharging the angularly
directed fluid flow, a fractional output port for diverting a fraction of
said fluid received by said major inlet at a first fluid pressure, and a
fractional input port for returning fluid diverted by said fractional
output into said angularly directed fluid flow in the area of said major
outlet and at a second fluid pressure less than said first fluid pressure.
22. In a fuel dispenser having a fractional flow indicator system, the
improvement comprising:
a fractional flow diverting element including a right angled inverted flare
elbow for angularly directing the flow of fluid, said elbow including a
major inlet for receiving fluid from a fluid supply conduit, a surface
opposite said major inlet for angularly directing the flow of fluid
through said elbow, a major outlet for discharging the angularly directed
fluid flow, a fractional output port for diverting a fraction of said
fluid received by said major inlet at a first fluid pressure, and a
fractional input port for returning fluid diverted by said fractional
output into said angularly directed fluid flow in the area of said major
outlet and at a second fluid pressure less than said first fluid pressure,
and
a flow indicator including a substantially rectangular base having
fractional flow input and output passages, a transparent dome-shaped cover
having a circular open end and a circumferential flange adjacent said open
end, one or more movable flow indicating bodies located within a chamber
created by said base and said cover, a retainer bracket for attaching said
cover to said base, resilient means providing a fluid tight seal between
said transparent cover and said base, an annular recess in the front
surface of said base adapted for receiving the open end of said cover and
intersecting with a small angled fluid inlet extending from said input
passage and a larger sized fluid outlet extending from said output
passage, and wherein the width of said annular recess is less than the
diameter of said flow indicating bodies and the depth of said annular
recess is sufficient to prevent said flow indicating bodies from blocking
said fluid outlet.
23. In a fuel dispenser having a fractional flow indicator system, the
improvement comprising:
a flow indicator including a substantially rectangular base having
fractional flow input and output passages, a transparent dome-shaped cover
having a circular open end and a circumferential flange adjacent said open
end, one or more movable flow indicating bodies located within a chamber
created by said base and said cover, a retainer bracket for attaching said
cover to said base, resilient means providing a fluid tight seal between
said transparent cover and said base, an annular recess in the front
surface of said base adapted for receiving the open end of said cover and
intersecting with a small angled fluid inlet extending from said input
passage and a larger sized fluid outlet extending from said output
passage, and wherein the width of said annular recess is less than the
diameter of said flow indicating bodies and the depth of said annular
recess is sufficient to prevent said flow indicating bodies from blocking
said fluid outlet.
Description
BACKGROUND OF THE INVENTION
This invention relates to liquid dispensing apparatus and, more
particularly, it concerns an improved visual flow indicating system for a
fuel dispenser.
Visual fluid flow indicators are well known in the fuel dispenser art and
conventionally employ a metallic base having a fluid inlet and a fluid
outlet which feed fluid thru a chamber created by the attachment of a
dome-shaped transparent cover to the base. A number of movable indicating
elements, such as, brightly colored balls are enclosed within the chamber
so that when fluid flows through the indicator, the movable flow
indicating elements circulate about the chamber and provide a visual
indication that flow is occurring and, thus, fuel is being dispensed. The
transparent cover also allows for a visual inspection of the fluid being
dispensed and an opportunity to ascertain whether or not air or gas is
being dispensed along with the liquid.
Early fuel pump flow indicator designs, such as described, for example, in
U.S. Pat. No. 1,730,118 issued to R. W. Cobb on Oct. 1, 1929, incorporated
relatively large flow indicators which accommodated the full fluid flow of
the liquid being dispensed. Such indicators were placed in the fuel
dispensing conduit between the fuel pump and the flexible dispensing hose.
Since all of the liquid being dispensed had to flow through the flow
indicator, any resistance to flow created by the flow indicator tended to
reduce the flow rate of the liquid being dispensed.
In an effort to reduce the size, bulk, and expense of the above-mentioned
large-sized flow indicators, fractional or partial flow indicator systems
were developed. In such a fractional flow indicator system, only a portion
of the fluid flowing through a dispenser conduit is diverted to a
relatively small-sized visual flow indicator. One example of such a
fractional flow indicator system is described in U.S. Pat. No. 2,678,624
issued to A. L. Grise et al on May 18, 1954.
Another example of a conventional fractional flow indicating system is
shown in FIGS. 1-3 of the drawings and generally designated by the
reference numeral 10. The flow indicating system 10 includes a fractional
flow diverting section generally designated 12 (FIGS. 1 and 3) which
provides a fractional fluid flow to a flow indicator 14 (FIGS. 1 and 2)
when fluid is being dispensed. The fractional flow diverting section 12
includes a fractional flow output 16 in a flow conduit 18 of a meter
support and diaphragm valve 20, a restrictor valve 22 (shown in a closed
position) located between the flow conduit 18 and a curved elbow 24 which
leads to a fluid conduit or pipe 26, and a fractional flow return 28 in
the curved elbow 24.
Typically, the fractional flow output 16 and return 28 are each
1/8N.P.T..times.1/4O.D.T. brass elbow fittings which are secured within
respective threaded openings in the conduit 18 and the curved elbow 24.
Lengths 30 and 32 of 1/4 inch copper tubing operatively connect the
fractional flow output 16 and return 28 to the flow indicator 14.
When the fluid pressure in the conduit 18 exceeds the back pressure
provided by the spring in the check valve 22, the valve 22 opens and
allows fluid to flow from the conduit 18 to the curved elbow 24, pipe 26
and eventually through a flexible hose and dispensing nozzle (not shown)
in a conventional manner. As fluid flows through the conduits 18 and 26,
the check valve 22 creates a pressure drop between the fluid in the
upstream conduit 18 and the downstream conduit 26. This pressure
differential created by the restrictor valve 22 is sufficient to induce
fluid flow through the fractional output 16, up through the tubing 30,
through the flow indicator 14, down through the tubing 32 and back through
the fractional flow return 28 into the curved elbow 24.
Although the restrictor valve 22 is effective at providing a sufficient
pressure differential to induce flow through the flow indicator 14, there
are several drawbacks associated with such a restrictor valve. Since
substantially all of the fluid being dispensed must pass through the
restrictor valve 22, the valve tends to reduce the fluid flow rate and
pressure. One method of compensating for this reduction in flow rate and
pressure is by using more expensive fuel pumps and motors capable of
producing greater fluid flow rates and pressures. Also, the restrictor
valve 22 includes one or more gaskets 34 and moving parts which are
subject to wear. Furthermore, assembly of the flow diverting section 12 of
flow indicating system 10 requires that respective threaded openings be
constructed in the conduit 18 and the curved elbow 24 to accommodate the
output 16 and the return 28.
With reference again to FIGS. 1 and 2 of the drawings, the flow indicator
14 includes a metallic base 36 having a threaded fluid inlet 38 and a
threaded fluid outlet 40. The inlet 38 receives a small-sized elbow
fitting 42 which in turn receives the upper end of the tubing 30. The
outlet 40 receives a straight fitting 44 within which the upper end of the
tubing 32 is received.
The flow indicator 14 further includes a dome-shaped glass cover 46 having
a circular base including a circumferentially extending flange 48 which
facilitates attachment of the cover 46 to the indicator base 36 by a clamp
ring 50. The clamp ring 50 is fastened to the indicator base 36 by four
counter sunk, flat head machine screws (not shown). An o-ring 52 is
provided between the clamp ring 50 and the glass flange 48 to ensure that
the flange 48 is not damaged. Another o-ring 54 is partially received
within an annular recess 56 in the indicator base 36 opposite the cover
flange 48 in order to provide a fluid tight seal between the base 36 and
the glass cover 46.
A fluid chamber 58 defined in large part by the inner surface of the glass
dome 46 houses a pair of movable flow indicating elements or balls 60. A
multi-part pedestal 62 made up of a round head machine screw 64, a washer
66, and a lock nut 68 is disposed within the chamber 58 with the shaft of
the machine screw 64 being received within a threaded bore 70 in the base
36. The washer 66 of the pedestal 62 keeps the balls 60 from blocking the
fluid outlet 40 and also serves to protect an inlet nozzle 72.
The nozzle 72 is partially received within an angled port 74 which
operatively connects the inlet 38 with the fluid chamber 58. The angled
port 74 and the nozzle 72 must both be machined to exacting tolerances so
that a fluid tight seal is formed between the inner surface of the angled
port 74 and the outer surface of the nozzle 72. The nozzle 72 includes a
small jet or opening 76 which accelerates the fluid passing through the
nozzle 72 and directs the fluid in a manner producing a positive
circulating motion of the fluid and the balls 60 in the chamber 58.
As shown most clearly in FIG. 1 of the drawings, the flow indicator 14 is
attached to a side wall 78 of a fuel dispenser 80 by an angled bracket
member 82. The glass dome 46 and a portion of the clamp ring 50 protrude
from a circular opening in an upper side sheath 84 to provide a visual
indication of fluid flow when fuel is being dispensed from the dispenser
80.
Even though the above-described flow indicator 14 provides an effective
visual indication of fluid flow through the fluid conduits 18 and 26,
construction and assembly of such an indicator is complicated and
expensive in that the indicator is made up of a number of parts and, as
such, requires a number of assembly steps and because the nozzle 72 and
angled port 74 must be machined to exacting tolerances.
In light of the foregoing, there is a need for an improved flow indicator
system, fractional flow diverting component and/or flow indicator.
SUMMARY OF THE INVENTION
In accordance with the present invention, the problems associated with
conventional flow indicators and systems are substantially overcome by a
flow indicator system by which flow in a fluid dispensing conduit is
visually indicated using an improved fractional flow diverting element
which does not restrict fluid flow, has no moving parts or special seals,
which can be manufactured from standard elbow components, and, as such, is
inexpensive to produce and enjoys a long service life. The present flow
indicator system further includes an improved flow indicator having a very
compact construction and few working parts, which is easy to manufacture,
and, as such, less expensive to produce and has a longer service life than
conventional indicators.
The fractional flow diverting element of the present invention utilizes a
venturi effect rather than a check valve to create the necessary
fractional flow pressure differential to induce a fractional fluid flow
through the flow indicator. The present invention not only does away with
the need for the check or restrictor valve of conventional fractional flow
diverting apparatus, but in so doing also eliminates the undesirable flow
restriction and reduction in fluid pressure experienced by conventional
diverting apparatus. Furthermore, by eliminating the check valve, the flow
diverting element of the present invention has no moving parts, requires
no special seals, and, thereby, enjoys a long service-free life.
The flow indicator of the present invention is much easier to manufacture,
less expensive, and has a longer operating life than conventional flow
indicators because, for example, it does not include a multi-part
pedestal, does not include a precisely machined diverting nozzle, and also
does not require a corresponding precisely machined fluid port. The flow
indicator of the present invention is very compact in that the indicator
base has been reduced to a rectangle measuring about
1.00.times.1.75.times.2.00 inches.
The invention is particularly though not exclusively adapted for use in
fuel dispensers and may find applicability in other fluid dispensing
apparatus where there is a need to have a visual indication of fluid flow
and/or a fractional flow pressure differential relating to fluid flow.
In the practice of the present invention, the improved fractional flow
diverting element and the improved flow indicator are either added to a
fuel dispenser during dispenser assembly, used to replace existing fuel
dispenser flow indicating components, or used to convert an existing
dispenser to a flow indicating type dispenser.
In accordance with a preferred embodiment, the flow diverting element of
the present invention is constructed from a standard elbow fitting which
is modified to include a fractional flow outlet port in the end face
opposite the major flow inlet and a fractional flow inlet port fitted with
a venturi tube in the end face opposite the major flow outlet. Further in
accordance with the preferred embodiment, the flow indicator of the
present invention includes a rectangular base, a transparent cover, two
resilient seals, a pair of movable indicating spheres, and a cover
retaining bracket which also serves as the flow indicator mounting
bracket.
Accordingly, a principal object of the present invention is to provide a
device for indicating fluid flow in a dispenser conduit without
restricting fluid flow therethrough. Another and more specific object of
the invention is the provision of a fractional flow diverting component
having no moving parts, no flow restrictions, no back pressure, no
resilient seals, which is easy to manufacture, and, as such, inexpensive
to produce. Yet another and more specific object of the present invention
is to provide such a fractional flow diverting element which is compatible
with existing dispenser components and conduits. Still another object of
the present invention is the provision of a flow indicator having a
compact construction with few working parts, which is easy to manufacture,
and, thus, inexpensive to produce. Another and more specific object of the
present invention is to provide an improved flow indicator which is
compatible with existing dispenser components and housing structures.
Other objects and further scope of applicability of the present invention
will become apparent from the detailed description to follow taken in
conjunction with the accompanying drawings in which like parts are
designated by like reference characters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross section illustrating a conventional fuel
dispenser and showing only those parts associated with the fractional flow
indicator system;
FIG. 2 is an enlarged cross section representing the flow indicator of FIG.
1;
FIG. 3 is an enlarged fragmentary cross section illustrating the flow
restricting valve of FIG. 1;
FIG. 4 is a cross section illustration of the fractional flow diverting
component of the flow indicating system of the present invention;
FIG. 5 is an end view of just the large elbow element of the flow diverting
component of FIG. 4:
FIG. 6 is a front view illustrating the base of the flow indicator in
accordance with the present invention;
FIG. 7 is a cross section of the base of FIG. 6 taken along line 7--7;
FIG. 8 is a midline cross section of the flow indicator base of FIG. 6
taken along line 8--8;
FIG. 9 is a stepped cross section of a fully assembled flow indicator in
accordance with the present invention taken along line 9--9 in FIG. 6;
and,
FIGS. 10, 11 and 12 are top, front and back views, respectively, of the
flow indicator of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 4 of the drawings, an exemplary embodiment of an improved
fractional flow diverting assembly in accordance with the present
invention is generally designated by the reference numeral 100 and shown
to include as major components a large-sized elbow 102, two small-sized
elbow fittings 104 and 106, and a venturi tube 108.
With reference to FIGS. 4 and 5 of the drawings, the relatively large elbow
102 is preferably a standard, commercially available, brass, valveless
inverted flare elbow which has been modified to include two threaded
openings 110 and 112 which serve as fractional output and input ports and
are adapted to receive the small-sized elbow fittings 104 and 106,
respectively. The elbow 102 includes as conventional features an
externally threaded fluid inlet 114 having a 3/4 inch diameter circular
bore 116 and an internally threaded fluid outlet 118 having a recessed,
3/4 inch diameter, circular bore 120 oriented perpendicular to the inlet
bore 116. The inlet bore 116 ends in a concave or countersunk surface 122
which serves to angularly redirect the fluid from the inlet 114 to the
outlet 118.
With reference again to FIGS. 4 and 5 of the drawings, the threaded opening
or fractional output port 110 extends from the concave interior surface
122 to a first planar exterior surface 124 of the elbow 102. As shown most
clearly in FIG. 5 of the drawings, the opening 110 is substantially
centrally locate with respect to the circular bore 116. The threaded
opening or fractional output port 112 extends from the circular bore 116
to a second planar exterior surface 126 of the elbow 102. The threaded
opening 112 is substantially centrally located with respect to the
circular bore 120.
In accordance with a preferred embodiment, the small-sized elbow fittings
104 and 106 are standard 1/4 inch O.D. tube flare brass elbow fittings
with the elbow fitting 106 being modified to include a circular
counterbore 128 sized to receive one end of the venturi tube 108. In
accordance with the same preferred embodiment, the venturi tube 108 is an
approximately 11/4 inch long section of 1/4 inch O.D. copper tubing. The
venturi tube 108 is attached to the counterbore 128 of the small elbow
fitting 106 by, for example, a Loctite compound.
The small-sized elbow fittings 104 and 106 are adapted to receive the lower
end of lengths of 1/4 inch O.D. copper tubing 130 and 132 which provide a
fractional fluid flow to and from a flow indicator. As such, the tubing
lengths 130 and 132 serve the same purpose as the tubing lengths 30 and 32
shown in FIG. 1.
It is preferred that the fractional flow diverting assembly 100 shown in
FIG. 4 of the drawings be substituted for the conventional curved elbow 24
and restrictor valve 22 of FIGS. 1 and 3 with the inlet 114 being threaded
into the flow conduit 18 of the meter support and diaphragm valve 20 and
the outlet 118 receiving one end of the dispensing conduit 26. Although
not preferred, it is to be understood that the flow diverting assembly 100
may be located in other positions along the dispensing conduit 26, for
example, between the curved elbow 24 and the dispensing conduit 26. In
this instance, the curved elbow 24 would not include the restrictor valve
22.
In the practice of the present invention, as fluid flows through the elbow
102, it enters the major inlet 114 and travels along the circular bore 116
in a first direction, passes around the venturi tube 108 and strikes the
opposing surface 122 which abruptly changes the direction of the fluid and
causes it to travel in a second direction perpendicular to the first
direction along the circular bore 120 and eventually out the major outlet
118. A fraction of the fluid which is directed at the surface 122 passes
through the threaded opening or port 110, into the small-sized elbow 104,
and along the tubing 130 to a flow indicator. The pressure of the fluid
passing through the threaded opening or port 110 is equal to or greater
than the pressure of the fluid entering the major inlet 114 due to the
positive velocity pressure created by an abrupt change in the fluid flow
direction. As fluid exits the elbow 102 through the major outlet 118, it
passes by a free or open end 134 of the venturi tube 108 and produces a
syphoning effect which tends to reduce the fluid pressure at the end 134
of the venturi tube 108 and induce fluid flow through the fractional
output port 110, through the small elbow 104, up through the tubing 130,
through a flow indicator, down through the tubing 132, through the small
elbow 106, and through the venturi tube 108 where the diverted fractional
fluid is returned to the main fluid stream in the area of the major outlet
118. As such, the fractional flow diverting assembly 100 of the present
invention utilizes a venturi effect to produce the necessary pressure
differential to induce the fractional fluid flow through a flow indicator.
In that the present invention does not rely upon the back pressure and
restriction provided by a conventional restrictor valve (FIG. 3), the flow
restriction and pressure reduction problems associated with conventional
fractional flow diverting elements are eliminated.
In a comparative example, a 9.5 gallons per minute flow rate was produced
using the fractional flow diverting assembly 100 of the present invention
as compared to an 8.8 gallons per minute flow rate provided by a
conventional flow diverting element including a restrictor valve (FIGS. 1
and 3). Thus, the pressure flow diverting assembly 100 in accordance with
the present invention provided a net increase in flow rate of 0.7 gallons
per minute. Further, at a 10 gallon per minute flow rate the fractional
flow diverting assembly 100 of the present invention did not produce a
measurable reduction in pressure of the fluid flowing through the elbow
102, while the conventional flow diverting element including the
restrictor valve (FIGS. 1 and 3) caused a three pounds per square inch
pressure drop which corresponds to the spring force in the restrictor
valve. Thus, the flow diverting elbow 100 of the present invention
provides for a fractional fluid flow for a visual flow indicator without
restricting flow and creating an undesirable pressure drop in the fluid
being dispensed.
Even though it is preferred that the flow diverting assembly 100 of FIGS. 4
and 5 be used in conjunction with the flow indicator of the present
invention as shown in FIGS. 6-12 and described below, it is to be
understood that the fractional flow diverting assembly 100 can be used
with existing flow indicator components and that the flow indicator of
FIGS. 6-12 can be used with conventional fractional flow diverting
elements or components.
As shown in FIGS. 6-12 of the drawings, an exemplary embodiment of the flow
indicator of the present invention is generally designated by the
reference numeral 200 and shown to include as major components a
rectangular, metal base 202 constructed from, for example, an aluminum bar
about 1.00 inch thick, 1.75 inches wide, and 2.00 inches long and having
fractional flow input and output passages 204 and 206, a dome-shaped cover
208 formed of a transparent material such as glass and having a circular
open end 210 and a circumferential flange 212 adjacent the open end, and a
pair of movable flow indicating bodies 214 located within a fluid chamber
216 defined by the base 202 and a cover 208.
In the illustrated embodiment, the transparent cover 208 is attached to the
front surface of the base 202 by a retainer bracket 220. The cover
retaining bracket 220 is secured to the base 202 by four machine screws
222, such as, four #10-32.times.1/2 inch screws received within
corresponding threaded openings 224 in the front surface 218 of the base
202.
With reference to FIGS. 6-9 of the drawings, the front surface 218 of the
base 202 includes an annular recess 226 having an outer diameter 228 and
an inner diameter 230. The outer diameter 228 of the annular recess 226
corresponds to the circumference of the flange 212 extending from the
opened end 210 of the transparent cover 208. The inner diameter 230 of the
annular recess 226 defines a pedestal 232 which projects into the chamber
216 and which is integral with the base 202.
With particular reference to FIG. 9 of the drawings, the depth of the
annular recess 226 in the base 202 provides for the placement of a first
o-ring 234 between the circumferential flange 212 and the base 202 and a
second smaller o-ring 236 between the circumferential flange 212 and the
retainer bracket 220. In this arrangement, the o-ring 234 provides a fluid
type seal between the transparent cover 208 and the base 202. The o-ring
236 allows for slight manufacturing variations and insures that the
transparent cover 208 is not damaged by the retainer bracket 220. The
width of the annular recess 226, that is the distance between the inner
and outer diameters 230 and 228, is large enough to accommodate the
intersection of the recess 226 with a small angled fluid inlet 238
extending from the input passage 204, for example, a 0.093 inch diameter
opening extending at a 60.degree. angle with respect to the longitudinal
axis of the passage 204, and a larger sized fluid outlet 240 providing
fluid communication with the output passage 206. The width of the annular
recess 226 is narrow enough, however, to restrict the movement of the
moveable flow indicating elements 214, such as brightly colored plastic
balls, to prevent blockage of the fluid outlet 240 during fluid flow
through the chamber 216.
The diameter of the angled fluid inlet 238 is about half that of the
diameter of the fluid outlet 240 so that during fluid flow through the
flow indicator 200 the small angled fluid inlet 238 produces a high
velocity fluid jet which creates a positive circulating fluid motion
within the chamber 216. This circulating fluid motion within the chamber
216 causes the moveable elements 214 to circulate about the chamber and,
thereby, provide a visual indication of fluid flow. Also, this positive
fluid circulation about the fluid chamber 216 and the location of the
fluid outlet 240 adjacent the upper edge of the transparent cover 208
(FIGS. 9 and 11) facilitates the removal of any air or gas from the
chamber 216.
As shown in FIGS. 9, 10, and 12 of the drawings, the input passage 204 is
adapted to receive a small-sized elbow fitting 242 which in turn receives
the upper end of the tubing length 130. Similarly, the output passage 206
is adapted to receive a small-sized elbow fitting 244 which is connected
to the upper end of the tubing 132. In this manner, the flow indicator 200
receives a fractional fluid flow from the flow diverting element 100 up
along the tubing 130, through the elbow 242, through the small angled
inlet 238, through the chamber 216, through the fluid outlet 240, through
the small-sized elbow 244, and returns this fractional fluid down through
the tubing 132 back to the diverting elbow 100. It is preferred that each
of the elbow fittings 242 and 244 are standard 1/4 inch O.D. tube flare
brass elbow fittings.
With reference again to FIGS. 10-12 of the drawings, the cover retaining
bracket 220 has a lateral extension 246 having a pair of circular openings
248 to facilitate the mounting of the flow indicator 200 to a fuel
dispenser. As such, the cover retainer bracket 220 serves the dual purpose
of not only attaching the transparent cover 208 to the base 202, but also
providing for the mounting of the flow indicator 200 to a fuel dispenser.
Hence, a separate indicator mounting bracket is not needed.
Thus, it will be appreciated that as a result of the present invention a
highly effective fractional fluid flow indicating system, fractional flow
diverting assembly, and flow indicator are provided by which the principal
object and others are completely fulfilled. It is contemplated and will be
apparent to those skilled in the art from the foregoing description and
accompanying drawing illustrations that variations and/or modifications of
the disclosed embodiment may be made without departure from the invention.
For example, the small-sized elbow fittings 104 and 106 of the flow
diverting assembly 100 and small-sized elbow fittings 242 and 244 of the
flow indicator assembly 200 may be replaced by straight fittings without
departure from the present invention. Furthermore, it is contemplated that
the 90.degree. elbow 102 shown in FIGS. 4 and 5 may be instead any one of
a variety of elbows having inlet and outlet bores or channels which
intersect at an angle of less than 180.degree.. Accordingly, it is
expressly intended that the foregoing description and accompanying
drawings are illustrative of a preferred embodiment only, not limiting,
and that the true spirit and scope of the present invention be determined
by reference to the appended claims.
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